This one was growing along side the rail trail near Masontown, WV.
I've been fascinated by these plants because they are considered living fossils, related to plants from the Carboniferous age 300 million years ago. When I was a kid living in Bath, NY, I discovered a bed of fossil Calamites in the cliff face of Mossy Bank, where I lived.
Though I've never dabbled with it, the Water Horsetail has a long history as a medicinal herb. Ancient Greeks and Romans used Horsetails to stop bleeding and treat kidney ailments, ulcers, and tuberculosis, and the ancient Chinese use it to treat superficial visual obstructions.